The present invention relates generally to a multiple image optics system, and more particularly to a multiple image optics system that enables a plurality of images to be parallel-processed for image processing or in neural networks.
To process a collection of information such as an image, studies have been intensively made of high-speed operation enabling computers. Since computer processing is in itself one-dimensional, it is required for high-speed processing of a collection of two-dimensional information such as an image that the processing speed of electronic circuits themselves be increased. However, it appears that some breakthrough in the processing speed of electronic circuits is hereafter not expectable because current electronic circuits have already been run at virtually maximum speed. For this reason, studies of parallel computers enabling parallel operation by use of a plurality of electronic circuits or electronic computers are being promoted. However, these studies are not so practical because interconnection delays or other problems arise from the need of making parallel connections between a plurality of electronic circuits or electronic computers.
On the other hand, light enables a variety of operations via modulation of amplitude, phase, frequency, polarization, and so on, and is very excellent in the high-speed and parallel processing capability. There is thus a possibility that light may be applied to high-speed and parallel processing of two-dimensional information, which is hardly achievable with electronic computers. In particular, parallel processing run on such a multiple image optics system as proposed in "OPTICAL REVIEW", Vol. 1, No. 2 (1994), pp. 248-253, "Automatic Design of One-To-Many Optical-Interconnections Lens System Using Aspherics" and illustrated in FIG. 1 is very effective for the high-speed capability. This multiplex image optics system is made up of a lens group 5 located on an object side thereof and a lens array 6 located on an image side thereof, said lens array 6 comprising lens elements 61, each having an optical axis parallel with the optical axis of the object-side lens group 5, which are two-dimensionally arranged at a constant pitch within a plane vertical to the optical axis of the object-side lens group 5. An input image is positioned in the vicinity of a front focal plane of the object-side lens group 5; light beams transmitting through the object-side lens group 5 are converted into parallel light beams to form an image in the vicinity of a back focal plane of each of the lens elements 61 in the image-side lens array 6, so that the input image can be replicated. This design is primarily characterized in that the effective F-number is minimized with the highest resolution because parallel light is incident on the image-side lens array 6, and in that there is no appreciable difference in how aberrations occur at the respective lens elements 61 because the optical axis of the image-side lens array 6 is parallel with that of the object-side lens group 5.
Image processing or neural networks require multiplexing for the purpose of increasing the quantity of information to be processed, and the speed of operation processing. So far, devices capable of controlling image displays by electrical or optical addresses such as spatial light modulators have been used as image display devices. In view of resolution and size, however, existing spatial light modulators and such do not have enough capability of displaying a plurality of images having a large quantity of information. When a plurality of images are concurrently displayed on a write surface of a spatial light modulator or the like, an area allocated to one image is naturally small. To increase the quantity of imagewise information as much as possible, therefore, it is required to make as full use of an allocated area on the write surface as possible. With a conventional multiple image optics system, however, it is substantially impossible to display an image having a large quantity of information because no full use is made of an area allocated to one image when displaying a plurality of images. Another problem with the conventional system is that it is impossible to increase the degree of multiplexing by increasing the number of lens elements forming an image-side lens array, because the ratio of the effective aperture of an object-side lens group with respect to the effective aperture of the image-side lens array is not large. Yet another problem with the conventional system is that it is designed to process monochromatic images alone; it cannot be used for color images or with white light sources because of being not well corrected for chromatic aberrations.